A canonical bundle formula

Abstract

A higher dimensional analogue of Kodaira’s canonical bundle formula is obtained. As applications, we prove that the log-canonical ring of a klt pair with k ≤ 3 is finitely generated, and that there exists an effectively computable natural number M such that |MKX| induces the Iitaka fibering for every algebraic threefold X with Kodaira dimension k = 1. © 2000 Applied Probability Trust.